Paul Johnson has written several concise biographies for general audiences about a wide array of landmark historic figures such as Churchill, Jesus, Napoleon and George Washington. In these minibiographies, he certainly has demonstrated a proven knack for distilling complex biographical issues into accessible stories of about 200 pages. And his latest successful biography, of the philosopher Socrates, is a further example of his narrative talents in bringing alive a rather obscure figure whom we all recognize but little understand from more than 2,400 years in the past.

The so-called Socratic “problem” is a paradox. From firsthand accounts in the dialogues of Plato and Xenophon, caricatures in Aristophanes’ contemporary comedy “Clouds” and anecdotes in fragments of lost essays, plays and later compendia, we know the rough contours of Socrates’ life and thought.

Or at least we should - except that his brilliant and wily student Plato used Socrates as his chief interrogator in about 36 extant dialogues. They probably were written over three decades, and the result is that we are never quite sure whether a particular dialogue represents a young Plato’s account of what Socrates actually said or what a maturing Plato thought his mentor should have said or what an aged Plato put into the mouth of his long-dead prop, Socrates - a literary device Mr. Johnson in melodramatic fashion sneers at as “the murder and quasi-diabolical possession of a famous brain.”

Mr. Johnson’s task of historical reconstruction is not helped by the fact that Socrates (469-399 B.C.) himself did not write anything and likewise lived a life of paradoxes. The philosopher praised and bantered with Athenian elites during the great years of the Athenian Empire, ensuring that even contemporaries were not sure whether he was a blowhard gadfly or the first true moralist of the new age of Western philosophical inquiry. In modest fashion, he claimed that he knew nothing, but in his cross-examinations of his philosophical rivals he sought to prove that he in fact knew a lot - and wanted others to grasp just that.

Socrates was relatively poor, but he gravitated to the wealthy; oligarchic perhaps in sympathy, he was adamantly loyal to the principles of existing Athenian democracy. He was a patriot and heroic military veteran who nevertheless was executed by a democratic court on trumped-up charges of corrupting the youth and introducing impiety.

Socrates lived during the best and worst times of Athenian splendor and hubris and knew the great Athenians of the age - Pericles, Sophocles, Plato and Xenophon. His death by execution through the drinking of hemlock remains an indictment of the moblike nature of Athenian democracy and its volatile jurisprudence, and later was usually cited - along with Thucydides’ infamous Mytilenean Debate and Melian Dialogue, and the macabre execution of the Athenian generals after the victory at Arginusae - as proof why constitutional republicanism was to be preferred to direct democracy.

Indeed, after the early Byzantine revision of the calendar into centuries, marked by either B.C. or A.D., Socrates’ death in 399 B.C., in symbolic fashion, became seen as a landmark, though dark, bookend to the great age of fifth-century B.C. Athenian liberality.

As Mr. Johnson notes, Socrates was a creature of the hustle and bustle of an Athenian renaissance fueled, in Florentine or Venetian fashion, by a rich commercial empire. His familiarity with a Pericles, Alcibiades or Plato would have been impossible without a singularly free Athenian democracy, lots of money and maritime power that created opportunities for intellectual tension and vibrancy unknown elsewhere - or a century earlier or later in Athens itself.

Socrates’ shabby appearance and his visible disdain of money and power were foils to the mores of his ostentatiously rich and sophisticated city. In some sense, he first established the image of the unworldly philosopher, oblivious to the conditions of the physical world about him. And yet he was no counterculture revolutionary but found his unorthodox moral and religious views protected and enhanced by his own patriotic and often dangerous military service, mentoring of the city’s elite and outward respect for religious orthodoxy.

Mr. Johnson also grasps well the essentials of Socratic philosophy - its novel emphasis on avoidance of vengeance that so influenced later neo-Platonist Christian apologists; his suspicion of the bodily appetites and physical world that compromised moral virtue and damaged the eternal soul; and his rejection of polytheism in favor of an all-knowing, all-moral universal and divinely guiding presence.

So why would Mr. Johnson offer yet another introductory sketch of Socrates - especially given the fact that the late classical philosopher Gregory Vlastos wrote a landmark accessible biography just 20 years ago that may never be matched?

Mr. Johnson certainly writes more concisely than most scholars, and he brings to his prose a wealth of anecdote and asides unknown to most academics. His Socrates comes alive not through arguments over Platonic dating or Pythagorean influence, but by wit and allusion to Jane Austen novels, Samuel Johnson, John Maynard Keynes, firsthand remembrances of Winston Churchill’s speeches and Richard Dawkins.

Occasional slips and errors do not detract from the generalist Johnson’s valuable overview. Socrates retreated from Delium, not Delos; Aristophanes, in fact, probably did caricature Pericles, though in postmortem and indirect fashion; ancient Greek script did have some punctuation marks, as we see occasionally in inscriptions - and was, of course, written entirely in, rather than lacking, “capital letters.”

It is true that “the works of the pre-Socratics, as they are called, are quite literally fragments,” but that does not mean that “no one who speculated about the cosmos has been fortunate enough to have his conclusions survive.” In fact, we know a great deal about the thought and “conclusions” of, for example, an Empedocles or Xenophanes, both from their own poems and synopses in later compilations.

Mr. Johnson ends at the heart of Socratic achievement, his radical invention of an ethical philosophy that dealt with everyday human moral dilemmas - what even in antiquity was considered calling philosophy down from the clouds of earlier abstract cosmology and natural science: “For Socrates saw and practiced philosophy not as an academic but human activity. It was about real men and women facing actual ethical choices between right and wrong, good and evil.”

Victor Davis Hanson is a classicist at the Hoover Institution at Stanford University and the author most recently of “The End of Sparta” (Bloomsbury, 2011).